Fig. 4 in Impairment of retinal function in yellow perch (Perca flavescens) by Diplostomum baeri metacercariae

Fig. 4. Paraffin sections of yellow perch (Perca flavescens) retinas and choroid infected with Diplostomum baeri, stained with H&E. A. Metacercariae in the choroid layer with thinning of the pigment epithelium. Retina in the unifected region on the far left of the image is in proximity to the rete mirabile. B. Pocket of metacercariae with melanin debris due to extensive damage to the choroid and pigment epithelium. C. Large pocket of metacercariae with melanin debris and loss of the pigment epithelium and photoreceptor layer (arrow). D. Uninfected region of the same eye shown in image C with normal retina, pigment epithelium and optic nerve. This was the only metacercaria seen in the vitreous humor of a perch on a histological section. E. Presence of the metacercaria increases the diffusion distance for O2 from the rete mirabile to the retina. Note damage to the pigment epithelium in locations of contact with the metacercaria. F. WrightGiemsa stain of the same region shown in image E. No inflammatory cells were detected. Bar = 100 μm. (For interpretation of the references to colour in this figure legend, the reader is referred to the Web version of this article.)